Search Results (750)

Radiolabelled nanoparticles are increasingly investigated as multifunctional platforms for cancer imaging, biodistribution tracking, dosimetry, and radionuclide-based therapy. This review focuses on three representative inorganic nanoplatforms: zinc oxide (ZnO), iron oxide-based, and gold (Au) nanoparticles. These systems were selected because they combine distinct physicochemical properties with versatile surface engineering and radiolabelling strategies. ZnO nanoparticles offer pH-responsive behaviour and drug-delivery potential; iron oxide-based nanoparticles provide magnetic functionality, Magnetic resonance imaging (MRI) compatibility, and opportunities for magnetic hyperthermia or local nanobrachytherapy; and Au nanoparticles enable stable surface functionalization, radiometal chelation, radiosensitisation, photothermal effects, and alpha or beta-emitter-based local therapy. The review critically discusses synthesis and surface-modification methods, chelator-mediated and chelator-free radiolabelling, coating-assisted and anchoring-mediated strategies, and the influence of these factors on radiochemical stability, biodistribution, tumour uptake, therapeutic response, toxicity, and clearance. A function-based comparison of the reviewed studies highlights that many systems demonstrate efficient radiolabelling and imaging capability, whereas fewer provide direct in vivo therapeutic efficacy, long-term toxicity, or metabolic clearance data. Overall, radiolabelled ZnO, iron oxide-based, and Au nanoparticles show strong potential for cancer theranostics, tumour-to-organ distribution, therapeutic benefit, and safety. Full article

Hydrogen sulfide (H₂S) is a contaminant for water quality, which can affect the eyes, respiratory system, and central nervous system, and may also cause damage to multiple organs such as the heart. Therefore, rapid and sensitive detection of trace H₂S is of great importance. In this work, a novel gold nanoparticle/2D porphyrin metal–organic framework nanocomposite (Au NPs/2D Cu-TCPP MOF) was prepared, and a novel electrochemical sensing method was established for the rapid determination of H₂S by differential pulse voltammetry (DPV). In 0.1 M PBS (pH 7.0), the detection limit of H₂S is as low as 0.03 μM, the linear range is 0.1–10 μM, and the response time is about 7 s. In addition, this method exhibits good stability and reproducibility, which can be applied to the rapid detection of H₂S in mine water samples. This study provides a reference for the development of new detection methods for H₂S in various complex environments. Full article

Developing zinc oxide-based nano-bactericides as alternatives to conventional chemical bactericides for controlling rice bacterial diseases has become a major research focus. In this study, ZnO nanoparticles were initially surface-modified and subsequently covalently conjugated with chitooligosaccharide (COS) via imine bonds to get a pH-responsive zinc oxide–chitooligosaccharide (ZnO–COS) delivery system. A series of physicochemical characterizations, including FTIR, UV-vis, XRD, and TGA, confirmed the successful synthesis of ZnO–COS NPs. Building on this foundation, the pH-responsive release behavior, foliar deposition performance, antibacterial activity, and biosafety of the nanoparticles were systematically investigated. The prepared ZnO–COS NPs exhibited pronounced acid-triggered Zn²⁺ release, together with enhanced wettability, spreadability, and retention on rice leaf surfaces, owing to COS incorporation. In both in vitro and in vivo assays against Xanthomonas oryzae pv. oryzae (Xoo), ZnO–COS NPs demonstrated effective antibacterial activity associated with bacterial cell damage and the activation of antioxidant defense responses in plants. Consequently, ZnO–COS NPs achieved a preventive efficacy of 56.0% against rice bacterial blight, surpassing those of ZnO (33.3%) and COS (14.3%). Furthermore, safety assessment confirmed the good biocompatibility of ZnO–COS NPs towards rice seed germination and seedling growth. In summary, the synthesised ZnO–COS NPs integrated pH-responsive release, improved foliar deposition, and enhanced antioxidant capacity of rice, offering a promising strategy for mitigating bacterial diseases in rice. Full article

In ulcerative colitis (UC), the therapeutic efficacy of nanoparticle (NP)-based drug delivery systems is limited by premature drug release, uptake or degradation of NPs during their passage through the harsh gastrointestinal tract (GIT) environment, poor colon targeting, and rapid NP clearance caused by diarrhea symptoms. This study focused on designing an advanced spatiotemporally controlled nanohybrid hydrogel drug delivery system to overcome these challenges. We developed a pH- and temperature-responsive polysaccharide-based hydrogel composed of chitosan (CS), β-glycerol phosphate disodium salt pentahydrate (GP), hydroxypropyl cellulose (HPC), and collagen type I (Col I), designated as CS/HHPC/Col I-GP. The hydrogel exhibited a dense and uniform porous reticular structure, with an average pore diameter of 127.45 ± 2.22 μm. The equilibrium swelling ratio of the CS/HHPC/Col I-GP was determined to be 32.10 ± 1.11 g/g, indicating excellent swelling capacity and sustained structural stability over 6 h—making it suitable for sustained drug release in the intestinal tract. Then, the prepared curcumin nanoparticles (CurNPs) were encapsulated into the CS/HHPC/Col I-GP hydrogel to form the CS/HHPC/Col I-GP-CurNPs composite. The polysaccharide-based hydrogel shell of the formulation withstood harsh gastrointestinal conditions, enabled targeted adhesion to the colon, and was specifically degraded by colonic enzymes. The CurNPs released in the colon benefit from their negatively charged characteristics, enabling accumulation at the positively charged inflamed sites and achieving sustained Cur release. The results of the gastrointestinal digestion simulation experiment showed that the cumulative release of CS/HHPC/Col I-GP-CurNPs was only 12.33 ± 2.17% in simulated gastric fluid (SGF) and reached 96.91 ± 1.98% in simulated colonic fluid (SCF) after 60 h. Cell and animal experimental data confirmed that the formulation significantly alleviated colitis symptoms by modulating the repolarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 phenotypes and deactivating the TLR4/MyD88/NF-κB pathway. Furthermore, the integrity of the intestinal mucosal barrier and the gut microbiota were enhanced. This study provides a promising strategy for the oral drug treatment of UC. Full article

Local pulmonary delivery offers a non-invasive application route for mRNA therapeutics with the potential for high bioavailability at the target-site of applications such as mucosal vaccination or the treatment of lung diseases. However, efficient delivery remains challenging due to major lung-specific barriers, particularly mucus. Herein, pH-responsive, amphiphilic xenopeptides comprising lipoamino fatty acids and oligoamino acids (OAAs) connected in distinct branched U-shape or bundle topologies were evaluated as mRNA polyplexes for delivery to A549 and Calu-3 lung cells under standard submerged or air–liquid interface (ALI) transfection conditions, and upon intratracheal application in BALB/c mice. Optionally, polyplexes were coated with negatively charged hyaluronic acid (HA) or colloidally stabilized with poly(ethylene glycol) (PEG). For U-shapes, hydrophobic modification of the OAA domain boosted their efficiency. Interestingly, best-performing formulations varied across transfection conditions. While the bundle topology showed the highest potential in submerged cell culture, U-shaped carriers were more efficient under ALI conditions. Polyplex surface modification with HA or PEG did not strongly alter in vitro transfections, whereas hydrophobized U-shape core polyplexes combined with surface modification enhanced their efficiency in vivo. Thus, the cationizable core and surface properties of mRNA nanoparticles require specific balancing in various lung cell models and lung. Full article

Synthetic polyinosinic:polycytidylic acid (poly(I:C)) offers an attractive cancer therapeutic by operating on two fronts at once, combining direct tumor cell killing with immunostimulatory activity. Yet, these dual functions can only be efficiently harnessed when intracellular delivery is sufficiently effective to enable poly(I:C) to reach and activate its intracellular receptors. We addressed this delivery challenge by developing pH-responsive formulations using lipoamino fatty acid xenopeptide (LAF-XP) carriers, composed of polar cationizable succinoyl tetraethylene pentamine (Stp) and apolar cationizable LAF building blocks in defined architectures. In particular, poly(I:C)-lipid nanoparticles (LNPs) formulated with bundle LAF₄-Stp₁ XP carriers displayed increased anti-tumoral activity at decreased dosage across multiple cancer cell models, compared to control formulations. In parallel, LAF-XP LNP-delivered poly(I:C) activated immune responses, including CXCL10 production by tumor cells, and activation of peripheral blood mononuclear cells (PBMCs), characterized by increased phenotypic markers (CD69 and LAMP-1/CD107a) and functional molecules (e.g., IFN-γ and granzyme B). Conditioned supernatant of pre-stimulated PBMCs with poly(I:C) reduced cancer cell viability, highlighting the contribution of PBMC-released factors to cancer cell death. Of particular novelty is the combination of poly(I:C) with siRNA-mediated survivin knockdown to increase apoptosis in cancer cells using the bundle LAF-XP LNP. Collectively, our findings establish efficient LAF-XP LNPs as a versatile platform that supports multi-layered therapeutic strategies. Full article

Periodontitis is a chronic inflammatory condition characterized by the progressive destruction of periodontal supporting tissues. With a global prevalence exceeding 60%, it poses a significant public health challenge. Traditional therapeutic approaches, primarily mechanical debridement, systemic antibiotics, and surgical interventions, often face limitations such as incomplete biofilm removal, rapid drug clearance, and systemic adverse effects. To overcome these challenges, recent research has shifted towards the development of intelligent biomaterials capable of modulating the pathological microenvironment. These microenvironment-responsive strategies leverage unique biochemical signatures, including acidic pH, elevated reactive oxygen species (ROS), and enzymatic dysregulation, to facilitate precise, on-demand drug delivery at the lesion site. This review examines recent advances from three integrated perspectives: (1) material platforms (hydrogels, microneedles, fiber membranes, microspheres, inorganic nanoparticles, and vesicles); (2) responsive design (pH, ROS, enzyme, glucose, and multi-stimulus cascade logic); and (3) spatiotemporal functional orchestration (early-stage microecological remodeling, mid-stage osteoimmunomodulation, and late-stage tissue regeneration). Additionally, we analyze critical translational challenges, including manufacturing scalability, clinical sterilization, and long-term biosafety, while discussing prospects for clinical implementation. This review aims to provide a strategic roadmap and theoretical guidance for the development of next-generation precision therapies for periodontitis. Full article

Chronic wounds, particularly those complicated by infection, present significant challenges in clinical management. The microenvironment of these wounds is typically characterized by the accumulation of reactive oxygen species (ROS) and abnormal local pH levels, both of which impede the healing process. Baicalin (BA), a natural flavonoid, exhibits anti-inflammatory activity, ROS-scavenging capability, and pro-healing effects. In this study, hydrogels were synthesized through photoinitiated radical polymerization of methacrylic anhydride (MAA) and dopamine (DA)-modified chondroitin sulfate (ChSMA-DA), grafting degrees of MA and DA were 58%, 23%, MPDA@MnO₂ nanoparticles (NPs), and methacrylated gelatin (GelMA). The gelation time, microtopography, swelling behavior, and water retention of the hydrogels were investigated, along with their degradation, rheological properties, and photothermal effects. The results indicate that swelling ratio (SR) and water retention (WR) of optimal HG-MPDA@MnO₂-M sample were 5.7, 82.42%, exhibited responsive behavior upon weakly acidic environment with pH 6.5 and elevated ROS levels, and exhibited a stable photothermal effect (photothermal conversion efficiency was 22.7%) under 808 nm near-infrared (NIR) light. Following the incorporation of the drug model BA, the cumulative release percentage over 24 h under the combined stimulation of pH 6.5, 1 mmol·L⁻¹ H₂O₂, and 808 nm NIR was 81.1%, significantly higher than either factor alone. These hydrogels show promise as an injectable dressing for chronic wounds, effectively integrating the internal microenvironment of the wound tissue with external NIR to modulate drug release. Full article

Current antibacterial sprays face major limitations, including rapid evaporation, short-lived efficacy, skin irritation, and poor adhesion to surfaces, highlighting an urgent need for a durable and biocompatible alternative. To address these challenges, we developed a ZIF-8-based spray (ZNS-WO20) composed of ZIF-8 nanoparticles dispersed in 50% ethanol and 20% OTES. OTES acts as a dispersant and binder, enabling wash-resistant coatings on gauze and glass. ZIF-8 exhibits pH-responsive Zn²⁺ release, achieving nearly 100% killing of S. aureus, E. coli, and methicillin-resistant S. aureus (MRSA) at 160 μg/mL through intracellular reactive oxygen species (ROS) generation. The spray maintains >95% antibacterial efficacy against S. aureus after five washing cycles and seven days of outdoor exposure, and causes no dermal irritation in rats. This work fills the gap for a long-lasting, skin-friendly antibacterial spray, showing promise for healthcare disinfection and surface protection. Full article

The growing demand for sustainable smart packaging arises from the urgent need to preserve food quality and minimize environmental waste. In this study, multifunctional gelatin-based pH-responsive indicator films were fabricated by incorporating anthocyanins extracted from Hibiscus x archeri W Watson (HAE) and zinc oxide nanoparticles (ZnO-NPs). The incorporation of HAE and ZnO-NPs enhanced surface hydrophobicity, as evidenced by an increase in the water contact angle from 99° to 106°. The Fourier transform infrared (FTIR) analysis verified the lack of new chemical bond formation, indicating that the interactions among components were primarily physical in nature. Distinct colour transitions in buffer solutions of differing pH demonstrated the films’ colorimetric behavior. The films exhibited strong antimicrobial activity against Listeria monocytogenes (18.961 mm), Salmonella typhimurium (18.969 mm), and Aeromonas hydrophila (18.237 mm), whereas the neat gelatin film showed no inhibitory zone. The films also demonstrated superior UV-blocking capacity, with an opacity value (1.34 a.u/mm) compared to the control gelatin film (0.79 a.u/mm). Notably, fish fillets wrapped with the films remained fresh for up to 10 days, compared to day 4 for the unwrapped samples. These findings highlight the considerable potential of multifunctional, active and intelligent packaging for food preservation and real-time freshness monitoring. Full article

Amphiphilic statistical copolymers are valuable synthetic macromolecules for the formation of small, well-defined nanoassemblies able to be utilized as nanocarriers for drug and/or gene delivery applications. In this work, the synthesis of amphiphilic linear statistical copolymers of the poly(benzyl methacrylate-co-dimethylaminoethyl methacrylate) [P(BzMA-co-DMAEMA)] type is described in three different comonomer compositions. Their synthesis was realized through a one-pot reversible addition-fragmentation chain transfer (RAFT) solution polymerization scheme. Further quaternization of the amine groups of DMAEMA with methyl iodide (CH₃I) resulted in cationic amphiphilic statistical copolymers. Macromolecular characterization was performed using size exclusion chromatography (SEC) and spectroscopic techniques (¹H-NMR and ATR-FTIR). The aggregation properties of the copolymers in aqueous media were studied via dynamic light scattering (DLS) and electrophoretic light scattering (ELS). Bimodal size distributions were determined in some cases. The BzMA to DMAEMA ratio determined aggregate size, with the copolymer of lower hydrophobic BzMA content producing smaller nanoparticles. Cryogenic transmission electron microscopy (cryo-TEM) showed the presence of spherical assemblies resulting from aggregation of primary micelles in the case of higher BzMA content. The copolymer aggregates experience dissociation at high salt concentration, and the pH-responsiveness of the amine precursors results in the formation of multifunctional potential nanocarriers. Full article

Reagentless glucose biosensors with redox mediator—polymerized 1,10-phenanthroline-5,6-dione (pPD)—were developed and electrochemically investigated. Three types of biosensors based on graphite rod (GR) electrodes modified by (i) 13 nm of gold nanoparticles (AuNPs), (ii) electrochemically synthesized dendritic gold nanostructures (DAuNSs), and (iii) platinum nanostructures (PtNSs) were prepared. All electrodes were modified by glucose oxidase (GOx), and the pPD was polymerized for 2 h. Thus, GR/AuNPs/GOx/pPD, GR/DAuNSs/GOx/pPD, and GR/PtNSs/GOx/pPD electrodes were developed and electrochemically characterized. The electrode without noble metal nanostructures (GR/GOx/pPD) was used as the control. The biosensor based on the GR/DAuNSs/GOx/pPD electrode exhibited the best performance, with the sensitivity of 2.58 μA/(mM cm²), the linear range up to 93.7 mM, the limit of detection 0.182 mM, the reproducibility and repeatability of 4.99 and 4.80%, and the storage stability (50% of initial current responses (t_1/2)) for up to 19 days. The achieved high resistance to interfering materials enabled precise glucose detection in real samples, including human serum and beverages. The technological solutions presented in this paper are anticipated to provide opportunities and benefits of developing novel enzymatic reagentless glucose biosensors based on noble metal nanostructures for use in clinical assays and general diagnostics, including blood glucose monitoring in people with diabetes. Full article

C-reactive protein (CRP) is one of the most essential biomarkers for the early detection of inflammation and infection. In this study, we developed a sensitive and selective electrochemical immunosensor for CRP detection, leveraging the unique properties of gold nanoparticles (AuNPs). A nanostructured layer of AuNPs was deposited onto a screen-printed carbon electrode (SPCE), followed by the formation of a self-assembled monolayer (SAM) of L-cysteine and EDC/sulfo-NHS chemistry. The antibody was covalently immobilized onto the modified electrode through optimized dual-crosslinking chemistry. Detection conditions were systematically optimized, with pH 8.0 in Tris buffer providing the best electrochemical response. Electrochemical characterization was performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) in a 5 mM K₃[Fe(CN)₆]/K₄[Fe(CN)₆] redox probe solution containing 0.1 M KCl. CRP detection was achieved by monitoring the increase in charge transfer resistance (Rct) upon specific binding of the target CRP antigen to the immobilized antibody. Spiked recovery experiments showed spiked recovery rates ranging from 98.01% to 107.14%, with a standard deviation below 4%. Regeneration studies demonstrated high efficiency, confirming the suitability of the sensor interface for repeated and reliable measurements. Under optimized conditions, the immunosensor exhibited excellent analytical performance, including a low limit of detection (LOD) of 0.16 µg/mL, a wide linear detection range of 5–100 µg/mL, high selectivity against 13 potential interferents (including inflammatory cytokines), and good reproducibility with a relative standard deviation (RSD) of 3.69%. The sensor also showed strong stability, retaining more than 95% of its signal after 15 days, and high regeneration efficiency of 97% over seven cycles. These results highlight the strong potential of the proposed immunosensor for point-of-care (POC) applications due to its simple fabrication, cost-effectiveness, user accessibility, and robust analytical performance. Full article

Background/Objectives: This paper describes the synthesis of silica nanoparticles (SiNPs) and their surface modification with amino and phosphate groups (SiNPs-NH₂-PO₃). The functionalized nanoparticles were subsequently loaded with the anticancer drug 5-fluorouracil (SiNPs-NH₂-PO₃-5-FLU) and further modified with PEG2000 (SiNPs-NH₂-PO₃-5-FLU-PEG2000). Methods: In this study, a one-step, two-phase, sol–gel method carried out at room temperature was used to synthesize the nanoparticles. The size and surface zeta potential of the created SiNPs were determined by DLS measurements. HPLC was used to determine the amount of drug loaded into silica nanoparticles and the drug release profile in two different pH environments (slightly acidic and physiological). Based on physicochemical characteristics, the SiNPs-NH₂-PO₃-5-FLU and SiNPs-NH₂-PO₃-5-FLU-PEG2000 formulations were chosen for comprehensive characterization. The cytotoxicity of the studied complexes was assessed in MCF7 breast cancer cells, while their ability to induce apoptosis in those cells was examined using specific immunofluorescence markers: active caspase-7, active poly(ADP-ribose) polymerase (PARP), and p53 protein. Results: Our findings demonstrate that SiNPs-NH₂-PO₃-5-FLU can induce a stronger apoptotic response than free 5-FLU at equivalent concentrations. We observed that drug release occurs not only under physiological conditions but is further enhanced in a mildly acidic environment (pH 5.0), characteristic of the tumor microenvironment. Conclusions: Most 5-fluorouracil formulations are administered as injectable solutions, resulting in systemic exposure and significant adverse effects. However, their encapsulation within nanoparticles could favor preferential drug release in the acidic tumor microenvironment, thus supporting targeted therapy and reducing toxicity to healthy tissues. Moreover, PEGylation of the nanoformulation allows prolonged and controlled release. Full article

Background: Platinum-based chemotherapy, including cisplatin and carboplatin, is widely used to treat various cancers, including ovarian cancer. However, its clinical application is limited by dose-limiting toxicities and resistance, with a poor 5-year overall survival rate for ovarian cancer (35–40%). In this study, we used ionisable lipids and developed pH-responsive lipid nanoparticles (LNPs) to address platinum-resistance in ovarian carcinoma. Methods: Cisplatin was loaded into three LNP systems containing monoolein (MO) and synthetic cationic ionisable lipids (OE-Mo, OA-Py, and OA-Pi) dispersed in Pluronic F-127 with 0.9% NaCl. Cisplatin-loaded LNPs (Cis-OE-Mo-NP, Cis-OA-Py-NP, and Cis-OA-Pi-NP) were characterised for size, zeta potential, and internal mesophase structure. Encapsulation efficiencies were determined via HPLC after removing free drug by ultrafiltration. In vivo efficacy was tested using cisplatin-resistant human patient-derived xenograft (PDX) models. Results: The LNPs were well dispersed with particle size of 219–250 nm and a drug loading of ~1.2 mg/mL. Encapsulation efficiencies were 62%, 59%, and 64%, for Cis-OE-Mo-NP, Cis-OA-Py-NP, and Cis-OA-Pi-NP, respectively. Small angle X-ray scattering (SAXS) results showed that the LNPs are pH responsive with structural transitions from a cubic to a hexagonal phase at an acidic pH. Among the tested formulations, Cis-OA-Py-NP resulted in the most significant reduction in tumour volume by ~60% compared to treatment with cisplatin alone. However, they also showed significant toxicity, including >10% weight loss and gross lung and kidney damage, as confirmed by histology. Conclusions: These findings highlight the potential of Cis-OA-Py-NP in reducing tumour volume but underscore the need for further optimisation to improve safety and therapeutic applicability. Full article